In motor vehicle engineering, “brake-by-wire” brake systems are becoming increasingly widespread. Such brake systems often includes electromechanical actuators which are each assigned to a wheel and are actuated by electronic signals which can be triggered by a braking desire of the vehicle driver or, for example, by an electronic stability program. The braking effect is in particular achieved by means of a friction brake. An actuator includes, in electromechanical brake systems, at least one electric motor, a transmission and a friction brake, wherein the desired application force is applied to the brake disks by the electric motor. In the case of electrohydraulic brake systems, the required hydraulic pressure can be made available by a central actuator, for example.
DE 102 007 021 286 A1 discloses an electromechanical brake system with a failsafe energy supply and a method for the failsafe supply of energy in an electromechanical brake system for vehicles. The brake system includes up to four brake modules, each assigned to a wheel, wherein each brake module includes a control device and an actuator, to which energy is supplied by a main energy supply unit via separate lines. Furthermore, the provision of a first and a second emergency energy supply unit with supply for in each case two of the brake modules with lines routed separately from one another is disclosed. In the application, no mention is made of how the functionality of the brake system can be maintained in the event of faults within the regulation of the electric motor of the actuator.
The object of the present invention consists in providing a method for improving the availability of an electromechanical actuator and a corresponding electronic device which function more reliably, i.e. which maintains the operation of the motor regulation and therefore of the actuator in particular in the event of the occurrence of a fault or a failure of the detection of individual or a plurality of state variables of the regulation of the electric motor of an actuator of an electromechanical or electrohydraulic brake system.
This object is achieved according to the invention by the method and the electronic device described herein.